Cut pork into about ¾” thickness. Beat with a meat mallet until meat is a thickness between ¼” – ½” thickness. Season with salt, pepper and coriander on both sides.
In a skillet, heat 2 tsp oil, once hot add the cook and sear on each side for about 3 minutes. Turn down the heat and cook for an additional 15-20 minutes.
Slice thee mushrooms and finely chop onion. In a skillet, saute mushrooms and onions on 1½ tsp oil, until onions are tender. Season to taste.
Transfer meat to a baking sheet. Add the crumbled feta cheese, then mushrooms and finally mozzarella.
Bake in preheated oven 8-10 minutes, until mozzarella is completely melted. Enjoy!